title: Rice Pi-ta gene Confers Resistance to the Major Pathotypes of the Rice Blast Fungus in the United States.
abstract: ABSTRACT The Pi-ta gene in rice prevents the infection by Magnaporthe grisea strains containing the AVR-Pita avirulence gene. The presence of Pi-ta in rice cultivars was correlated completely with resistance to two major pathotypes, IB-49 and IC-17, common in the U.S. blast pathogen population. The inheritance of resistance to IC-17 was investigated further using a marker for the resistant Pi-ta allele in an F(2) population of 1,345 progeny from a cross of cv. Katy with experimental line RU9101001 possessing and lacking, respectively, the Pi-ta resistance gene. Resistance to IC-17 was conferred by a single dominant gene and Pi-ta was not detected in susceptible individuals. A second F(2) population of 377 individuals from a reciprocal cross between Katy and RU9101001 was used to verify the conclusion that resistance to IC-17 was conferred by a single dominant gene. In this cross, individuals resistant to IC-17 also were resistant to IB-49. The presence of Pi-ta and resistance to IB-49 also was correlated with additional crosses between 'Kaybonnet' and 'M-204', which also possess and lack Pi-ta, respectively. A pair of primers that specifically amplified a susceptible pi-ta allele was developed to verify the absence of Pi-ta. We suggest that Pi-ta is responsible for resistance to IB-49 and IC-17 and that both races contain AVR-Pita genes.
authors.forename: Yulin
authors.initials: Y
authors.lastname: Jia
authors.forename: Zhonghua
authors.initials: Z
authors.lastname: Wang
authors.forename: Robert G
authors.initials: RG
authors.lastname: Fjellstrom
authors.forename: Karen A K
authors.initials: KA
authors.lastname: Moldenhauer
authors.forename: Md A
authors.initials: MA
authors.lastname: Azam
authors.forename: James
authors.initials: J
authors.lastname: Correll
authors.forename: Fleet N
authors.initials: FN
authors.lastname: Lee
authors.forename: Yingwu
authors.initials: Y
authors.lastname: Xia
authors.forename: J Neil
authors.initials: JN
authors.lastname: Rutger